How many grams of O2(g) are needed to completely burn 17.3 g of C3H8(g)?

Answer 1

C3H8 + 5O2 ==> 3CO2 + 4H2O

mols C3H8 = grams/molar mass = ?
Using the coefficients in the balanced equation, convert mols C3H8 to mols O2. That's ?mols C3H8 x (5 mols O2/1 mol C3H8) = ?
Now convert mols O2 to grams. grams = mols x molar mass = ?